Sewing machine



Feb. 27, 1934. H. F MAN ET AL 1,949,073

SEWING MACHINE Filed May 12, 1933 2 Sheets-Sheet l ank/A 5% Meg.

Feb. 27, 1934. H, F, GRUMAN ET AL 1,949,073

SEWING MACHINE Filed May 12. 1933 2 Sheets-Sheet 2 Mam/2 Patented Feb.27, 1934 UNITED STATES PATENT OFFICE SEWING MACHINE Horace F. Gruman andCharles L. Knower, Kirkwood, Mo.

This invention pertains to sewing machines.

One of the objects of this invention is to provide a machine of compactconstruction which will occupy a small space.

Another object is to provide such a machine capable of sewing a seam orseams including a plurality of stitching operations.

Another object is to provide a novel stitchforming mechanism forsuch amachine.

Further objects will appear from the following description taken inconnection with the accompanying drawings, in which:

Figure 1 is a perspective view of a sewing machine embodying thisinvention showing parts broken away so as to disclose the mechanism;

Figure 2 is a longitudinal sectional view taken just inside the frontwall of the casing in Figure 1;

Figure 3 is a rear view of the looper bracket Figure 4 is a plan view ofthe same;

Figure 5 is a rear view of the machine;

Figure 6 is a section on line 6--6 of Figure 5; and

Figure 7 is a section on line '7---'? of Figure 5.

This machine is intended for sewing a seam adapted to join two pieces ofmaterial and finish the seamed edge. The seam produced by the mechanismillustrated in the drawings includes a joining and reenforcing seam ofthe two-thread chain stitch type running along and near the edges of thepieces to be joined and an overstitch seam integral with and outside ofthe joining seam and arranged to overcast the edges to provide a finishtherefor. This is a scam in frequent use on many types of clothing andthe like. It is desirable to provide a machine capable of producing aseam of this type at a high rate of speed.

A sewing machine in order to be capable of successful operation at ahigh speed must be so arranged that all of its operating parts arerigidly supported and controlled for accurate movement so that whileoperating at high speeds there is no change of vibration being set up inthe different elements which would tend to destroy the accurate timingof the stitching mechanism.

Referring to the drawings, 1 designates a base or frame or casing which,in accordance with the embodiment illustrated, is made in box form. Thisbase is ordinarily formed of cast iron, or similar material, and thebearings for many of the moving parts may conveniently be formed in thecasting. Suitably journaled in the base 1 and running longitudinallythereof is the main shaft 2 which protrudes on the outside of the casingand has mounted thereon a suitable pulley 3 for driving the machine. Theupper part of the casing may be formed separately and attached to thebase 1 by a hinge 4, or the like, so as to provide a lid 5 which may beopened for access to the mechanism or closed during operation so as tohouse and protect the mechanism. Journaled in a pedestal 6 on the base 1is an auxiliary shaft 7 which may be arranged parallel to the main shaft2 and which carries a curved needle arm 8 adapted to carry a pluralityof needles 9 and 10. The shaft 7 carries a crank arm 11 provided with asuitable counterweight 12. This crank arm is connected by a pitman 13with an eccentric on the shaft 2. Rotation of the main shaft, therefore,will operate through this pitman and crank connection to oscillate theshaft 7 in order to operate the needle arm 8 which rocks about the shaft7 as a center, the needles 9 and 10 being appropriately curved.

A looper bracket 14 is pivoted on a sleeve 15 which, in turn, isjournaled in a bearing 16 adjustably mounted on the base 1. The axis ofthe bearing 16 is not at right angles to the shaft 2, but is inclinedthereto so as to cause the looper bracket 14 to oscillate in an angularplane. The bracket 14 has jointed thereto by a ball joint 17 anadjustable link 18 which is jointed at its other end by a ball joint 19to an arm 20 fixed to a rock shaft 21 journaled transversely on thebase 1. The shaft 21 carries at its rear end a forwardly extending arm22 which is connected by a ball joint to an upstanding link 23 which inturn is similarly connected to an arm 24 fixed to the shaft 7. Thus theoscilation of the shaft '7 operates through this train of connections tooscillate the looper bracket 14 and this movement is accurately timedwith respect to the needle arm 8 as it is driven from the sameoscillating shaft.

The looper bracket 14 carries two loopers. The rear looper 25 isadjustably fixed in the bracket 14 as by a clamping screw 26, or thelike. This looper is positioned to cooperate with the rear needle 10 aswill be more fully described hereinafter. The forward looper 27 isformed with a straight shank 28 which is journaled' to swivel in thebracket 14. The shank 28 has fixed thereto at its lower end an arm 29which extends opposite to but spaced from the end of the bearing 16. Thesleeve 15 carries an endwise slidable headed stud 30 pressed outwardlyby a spring 31 supported by a screw plug 32 in the end of the sleeve.The stud 30 protrudes from the end of the sleeve and bears against theend of the arm 29 so as to maintain the same in its outer position.

Arranged to bear against the opposite side of the arm 29 is a finger 33mounted on a shank 34 suitably journaled in the base 35 of the bearing16. The other end of the shank 34 has fixed thereto an arm 36 pivoted bya stud 3'7 to a pitman 38 operated by an eccentric on the main shaft 2.The rotation of the main shaft, therefore, acts to rock the shank 34and, therefore, the finger 33. This finger acting on the arm 29 causesthe looper to swivel on the shank 28 which imparts to the looper itslateral vibrating movement which chanegs it from side to side of theneedle for making a chain stitch. The looper 2'7 is positioned tocooperate with the forward needle 9. Both the needles and the looperscarry threads and co operate to form a two-thread chain stitch in theusual manner.

Arranged to cooperate with the looper 25 and the needle 10 is anovercasting looper 39. This looper is mounted on a lever to pivoted at41 on an arm 42 which in turn is pivoted at 43 on the base 1. The pivots41 and 43 have extended bearings so that the arm is rigidly supportedagainst side play. The right-hand end of the lever is pivoted at 44 toone arm 45 of a bell crank pivoted on a stud 46 suitably supported inthe base 1. The other arm 47 of this bell crank is connected by a link48 to an arm 49 fixed to a transverse cross shaft 56 suitably journaledin the walls of the casing. The cross shaft 50 has fixed thereto an arm51 connected by a ball joint 52 to a pitman 53 operated by an eccentricon the main shaft 2. In the operation of this train of connections thepitman 53 rocks the transverse shaft 50 which acts through the link 18to rock the bell crank 4'7, 45. This operates to swing the right-handend, Figure 2, of the lever lil'downwardly and to the left. The downwardmovement causes the looper 39 to rise while the movement to the leftmoves the lever bodily to the left on the swinging arm 42 so as to carrythe looper 39 longitudinally toward and from the needles. Thesemovements are so coordinated that when the needle 10 has pierced thework and starts to recede the looper 25 enters the needle loop andcarries it into the path of the forward moving looper 39. The latterlooper takes the looper from the looper 25, takes it up past the throatplate to a position above the work, and then into the path of the needle10 which again enters the loop on its down stroke. This forms anovercasting binding seam in a manner well known in the art. Since thelooper bracket 14 is pivoted on an inclined pivot in the bearing 16 itsmovement is inclined to that of the looper 39 so that it may pass on oneside of the needle 10 and cross over to the other side of the looper 39.

Pivoted at 5% on a suitable stud in the pedestal 6 is a trimmer arm 55.This arm is pivoted at 56 to a pitman 5'7 operated by an eccentric onthe main shaft 2. This gives the arm 56 up and down movements so as tocause a trimming cutter 58 mounted in the end thereof to cooperate witha corresponding stationary cutter 59 adjustably mounted on a fixedportion of the base.

The trimmer arm v is pivoted on a shaft or stud 68 working in a socketin the pedestal 6 and tensioned by a spring 69 in said socket to hold itin engagement with the stationary cutter 59. In order to provide fortaking up the tension on the trimmer arm when it is necessary to replacethe stationary cutter 59, a sliding bar '70 is slidably mounted on abracket 71 and has a turned over end '72 extending beyond and adapted toengage the trimmer arm 55. The other end of the arm '70 has an abutment'73 adapted to be engaged by a manually operable cam '74 provided with ahandle '75. By means of the handle '75 the cam '74 may be rotated andoperates by engagement with the abutment '73 to retract the bar '70.This action causes the turned over end '72 to engage the trimmer arm toretract the same so as to relieve the pressure between the cutters.

Mounted on a shaft 60 journaled in the pedestal 6 is a curved presserfoot arm 61 carrying a presser foot adapted to cooperate with a throatplate 62 to properly hold the work being operated upon. A feed dog 63 ofany suitable type may be provided to feed the work. The shaft 66 may betensioned by a spring 65 engaging a lever 66 pivoted on the shaft 60 soas to move the presser foot yieldingly into engagement with the throatplate. An arm 64 fixed on the shaft 66 has an adjusting screw 67 bearingon the lever 66 and which may be connected to a treadle, or the like,not shown, so that the pressure foot may be lifted at the will of theoperator.

The feed dog 63 is mounted on an arm '76' pivoted on a shaft '77journaled in a rocking bracket '79 pivoted on a shaft journaled inbearings 81 in the base 1. The bearings 31 may be in the form of sleevesas shown in Figure 5 which are secured by set screws 32 in their lugs onthe base 1. It will be seen that the bracket '79 and, therefore, the arm76 which carries the feed dog may be adjusted longitudinally of themachine by loosening and shifting the sleeves 81. This providesfor'accurately adjusting the feed dog 63 in its relation to the throatplate 62.

The rocker bracket '79 has a slot '78 adapted to receive a slide 83 towhich is pivoted a pitman 84 operated by an eccentric 85 on the mainshaft 2. By adjusting the slide 63 along the slot '78 the throw of thefeed dog may be lengthened or shortened as desired.

In the operation of this machine the work is fed to the machine fro-mthe left of Figure 1 over the throat plate 62 with the edges to bejoined projecting to the right. This brings the edges under the trimmingcutter 53 to be trimmed at substantially the same time that the goodsarrives at the needles 9 and 10. The needle 9 is set slightly to theleft of the needle 10 so that the reenforcing seam will be run slightlyinside of the cover seam. The goods is fed by the dog 63 which is givena suitable oscillating movement by any suitable mechanism, which neednot be described in detail. The needle 9 cooperating with the looper 27forms a two-thread chain stitch to join the two pieces of materialtogether. The needle 10 cooperates with the loopers 25 and 39 to form acover seam over the trimmed edges of the material. This cover seam isrun just outside of the reenforcing seam so that the latter seam formsan adequate reenforcement to prevent the cover seam being pulled out bythe tension on the same.

Having thus described the invention, what is claimed is:

1. A sewing machine of the character described, comprising, a base, amain shaft journaled horizontally on said base, an auxiliary shaftjournaled on said base substantially parallel to and rearwardly of saidmain shaft, operating connections between said shafts, a needle armfixed to said auxiliary shaft and extending forwardly over said mainshaft, a looper bracket pivoted on said base below the forward end ofsaid arm, a looper movable for vibration on said bracket, connectionsfrom said auxiliary shaft to swing said bracket on its pivot, andconnections from said main shaft to vibrate said looper on said bracket.

2. A sewing machine of the character described, comprising, a base, amain shaft journaled horizontal-1y on said base, an auxiliary shaftjournaled on said base substantially parallel to and rearwardly of saidmain shaft, operating connections between said shafts, a needle armfixed to said auxiliary shaft and extending forwardly over said mainshaft adapted to receive a pair of needles, a looper bracket pivoted onsaid base below the forward end of said arm, a looper fixed on saidbracket adapted to cooperate with one of the needles, a second loopermovable for vibration on said bracket adapted to cooperate with thesecond needle, and operating connections to rock said bracket on itspivot and vibrate said second looper on said bracket.

3. A sewing machine of the character described, comprising, a base, amain shaft journaled horizontally on said base, an auxiliary shaftjournaled on said base substantially parallel to and rearwardly of saidmain shaft, operating connections between said shafts, a needle armfixed to said auxiliary shaft and extending forwardly over said mainshaft, a looper pivoted on said base below the forward end of saidneedle arm, connections from said auxiliary shaft to operate saidlooper, a loop carrier, an arm pivoted on said base and on which saidlooper carrier is pivoted, a bell crank, operating connections from saidmain shaft to said bell crank, and connections between said bell crankand said loop carrier adapted to move the latter to carry a thread loopupwardly from said looper.

4. A sewing machine of the character described, comprising, a base, amain shaft journaled horizontally on said base, an auxiliary shaftjournaled on said base substantially parallel to and rearwardly of saidmain shaft, operating connections between said shafts, a needle armfixed to said auxiliary shaft and extending forwardly over said mainshaft adapted to receive a pair of needles, a looper bracket pivoted onsaid base below the forward end of said arm, a looper fixed on saidbracket adapted to cooperate with one of the needles, a second looperswiveled for vibration in said bracket adapted to cooperate with thesecond needle, operating connections to rock said bracket on its pivotand vibrate said second looper in said bracket, a. loop carrier, an armpivoted on said base and on which said loop carrier is pivoted, a bellcrank, operating connections from said main shaft to said bell crank,and connections between said bell crank and said loop carrier adapted tomove the latter to carry a thread loop upwardly from said first looper.

5. In a sewing machine of the character described, a base, a main shaftjournaled horizontally on said base, an auxiliary shaft journaled onsaid base substantially parallel to and rearwardly of said main shaft,operating connections between said shafts, a needle arm fixed to saidauxiliary shaft and extending forwardly over said main shaft, a trimmerarm pivoted on said base rearwardly of said main shaft and extendingforwardly thereof, and connections from said main shaft extendingupwardly to operate said trimmer arm.

6. In a sewing machine of the character described, a base, a main shaftjournaled horizontally on said base, an auxiliary shaft journaled onsaid base substantially parallel to and rearwardly of said main shaft,operating connections between said shafts, a needle arm fixed to saidauxiliary shaft and extending forwardly over said main shaft, a trimmerarm pivoted on said base rearwardly of said main shaft and extendingforwardly thereover, means for tensioning said trimmer arm, and meansadapted for adjustment to support such tension.

7. In a sewing machine of the character described, a base, a looperbracket pivoted thereon, means for rocking said bracket on its pivot, alooper having a shank swiveled in said bracket, and means for vibratingsaid looper about said shank as an axis.

8. In a sewing machine of the character described, a base, a looperbracket pivoted thereon, means for rocking said bracket on its pivot, alooper having a shank swiveled in said bracket, means for yieldinglytensioning said looper in said bracket, and vibrating means opposingsaid tensioning means adapted to vibrate said looper about the axis ofits shank.

9. In a sewing machine of the character described, having a base, a mainshaft journaled horizontally on said base, an auxiliary shaft journaledon said base substantially parallel to and rearwardly of said mainshaft, operating connections between said shafts, a needle arm fixed tosaid auxiliary shaft and extending for- 'wardly over said main shaft, atransverse shaft above said main shaft and connected thereto for rockingmovement, a looper carrier, an arm pivoted on said base and on whichsaid loop carrier is pivoted, a bell crank, operating connections fromsaid transverse shaft to said bell crank, and connections between saidbell crank and said loop carrier adapted to move the latter to carry athread loop upwardly from said looper.

10. A sewing machine of the character described, comprising, a base, amain shaft journaled horizontally on said base, an auxiliary shaftjournaled on said base substantially parallel to and rearwardly of saidmain shaft, operating connections between said shafts, a throat plate, aneedle arm fixed to said auxiliary shaft and extending forwardly oversaid main shaft, a feed dog cooperating with said throat plate, apivoted bracket for operating said dog, and means for adjusting saidbracket adapted to center said dog in said throat plate.

11. In a sewing machine of the character described, a needle arm adaptedto receive a plurality of needles, an oscillating looper bracket, and aplurality of thread-carrying loopers mounted on said bracket, one ofsaid loopers being fixed in position thereon to cooperate with one ofsaid needles, and a second of said loopers being movably mounted to havea sidewise vibrating motion on said bracket in order to form a threadtriangle for the entrance of a second of said needles.

12. In a sewing machine of the character described, a needle arm adaptedto receive a plurality of needles, an oscillating looper bracket, and aplurality of thread-carrying loopers mounted on said bracket, one ofsaid loopers being fixed in position thereon to cooperate with one ofsaid needles, and a second of said loopers being laterally movable onsaid bracket to cooperate with another of said needles.

HORACE F. GRUMAN. CHARLES L. KNOWER.

